class_docstr: Test Fbank FE using 8k/16k wav files.
code: def test_zcr(self):
      wav_path = str(Path(PACKAGE_OPS_DIR).joinpath("data/sm1_cln.wav"))
  
      with self.cached_session(use_gpu=False, force_gpu=False):
          read_wav = ReadWav.params().instantiate()
          input_data, sample_rate = read_wav.call(wav_path)
          input_data = input_data / 32768
  
          zcr = Zcr.params(
              {"window_length": 0.025, "frame_length": 0.010}
          ).instantiate()
          zcr_test = zcr(input_data, sample_rate)
  
          output_true = np.array(
              [
                  0.406250,
                  0.418750,
                  0.425000,
                  0.407500,
                  0.393750,
                  0.392500,
                  0.388750,
                  0.417500,
                  0.427500,
                  0.456250,
                  0.447500,
                  0.386250,
                  0.357500,
                  0.282500,
                  0.232500,
                  0.262500,
                  0.282500,
                  0.295000,
                  0.220000,
                  0.157500,
                  0.125000,
                  0.107500,
                  0.100000,
                  0.092500,
                  0.092500,
                  0.095000,
                  0.097500,
                  0.105000,
                  0.100000,
                  0.112500,
                  0.120000,
                  0.132500,
                  0.130000,
                  0.135000,
                  0.112500,
                  0.120000,
                  0.090000,
                  0.080000,
                  0.070000,
                  0.080000,
                  0.087500,
                  0.092500,
                  0.097500,
                  0.097500,
                  0.112500,
                  0.090000,
                  0.065000,
                  0.087500,
                  0.175000,
                  0.240000,
              ]
          )
  
          self.assertAllClose(
              zcr_test.eval().flatten()[:50], output_true
          )
  
file_path: delta/delta/data/frontend/zcr_test.py
imports: import os
  from pathlib import Path
  import numpy
  import delta.compat
  from core.ops import PACKAGE_OPS_DIR
  from delta.data.frontend.read_wav import ReadWav
  from delta.data.frontend.zcr import Zcr
label_desc: Use image node_id 1 for calling the ZcrTest obj's underlying member method code with example usage: obj.test_zcr() without return types